BestBuy.com — a major Apple reseller — has now stopped shipping the current-generation of Apple’s ultraportable notebook as an upcoming refresh becomes ever more apparent.

Visitors to the BestBuy.com website are no longer able to purchase the device for home delivery, with a notice that clearly states the device is “Not Available for Shipping.”

The change suggests Best Buy’s stock is now so limited that it must dedicate any remaining units to its popular retail stores. BestBuy.com doesn’t offer a date for when the MacBook Air may be available to order again, but we’re guessing it won’t be until after the upcoming product refresh.

9to5 Mac says that a number of Best Buy’s stores are also “exceptionally low on MacBook Air stock,” according to its sources, and Amazon is also running low in multiple countries.

The upcoming refresh to Apple’s MacBook Air lineup has now been a talking point for some time, with sources revealing last week that production for the next-generation device is set to “run in full gear” during July, as Apple prepares for a launch alongside Mac OS X Lion.

We’d advise you to put your new MacBook Air purchase on hold for a few weeks if you can — otherwise it won’t be long before you’re the owner of an outdated device.